Jasmonates are a family of plant hormones that regulate plant growth, development and responses to stress. COI1 is an F-box protein that functions as the substrate-recruiting module of the Skp1-Cul1-F-box protein (SCF) ubiquitin E3 ligase complex. The role of COI1-mediated JAZ degradation in jasmonate (JA) signaling is analogous to auxin signaling through the receptor F-box protein transport inhibitor response 1 (TIR1) , which promotes hormone-dependent turnover of the AUX/IAA transcriptional repressors. The crystal structure of COI1 reveals a TIR1-like overall architecture, with an N-terminal tri-helical F-box motif bound to ASK1 and a C-terminal horseshoe-shaped solenoid domain formed by 18 tandem leucine-rich repeats. This entry represents the N-terminal F-box domain which is also found in other auxin signaling f-box proteins such as AFB1, AFB2 and AFB3 [1].

1: Jasmonate perception by inositol-phosphate-potentiated COI1-JAZ co-receptor. Sheard LB, Tan X, Mao H, Withers J, Ben-Nissan G, Hinds TR, Kobayashi Y, Hsu FF, Sharon M, Browse J, He SY, Rizo J, Howe GA, Zheng N; Nature. 2010;468:400-405. PMID:20927106